Lex talionis: Testosterone and the law of retaliation

Research examining both the organizing and activating effects of testosterone in one-shot bargaining contexts has been vexed by inconsistencies. Some research finds that high-testosterone men are more likely to reject unfair offers in an ultimatum game and exogenous administration of testosterone to men leads to less generous offers. In contrast, other research finds that higher prenatal exposure to testosterone predicts more generous dictator game offers and administering testosterone to women leads to more generous ultimatum game offers. The current research seeks to resolve these inconsistencies by examining how the organizing effects of testosterone affect bargaining behavior. Because testosterone is associated with status seeking and concerns with social reputation, we hypothesized that testosterone would predict aggressive bargaining but only after provocation. Two studies found that prenatal testosterone exposure, as measured by 2D:4D ratio, led to aggressive responses for both males and females, but only after they received unfair offers. Furthermore, perceptions of fairness violations moderated but did not mediate the effect of testosterone on retributional responding. These results suggest that the organizing effects of testosterone have consistent effects on bargaining behavior for both males and females but its predictive ability requires some form of provocation to emerge.